The increase of a vehicle using fossil fuel like gasoline, diesel or the like causes serious energy problems due to the rapid increase of demand for the fossil fuel. Also, the increase of the vehicle brings about not only both the environmental pollution due to excess emission of carbon dioxide and environmental problems like the increase of greenhouse gas concentrations, etc., but also various economic problems caused by rapid fluctuation in the price due to an imbalance between supply and demand, etc.
To solve the problems, active technical developments are made, which improves a fuel efficiency through being lighter and high efficiency or replaces the fossil fuel with green energy in the automotive industry.
A technology for replacing the fossil fuel with green energy is now the most actively applied to the development of an electric vehicle or a hybrid vehicle, etc. The electric vehicle or hybrid vehicle has been partially commercialized.
A secondary battery which can be reused by being charged is used as a main power source or an auxiliary power source of the electric vehicle or the hybrid vehicle. The secondary battery is used as the main power source or the auxiliary power source in such a manner that a battery module obtained by generally combining a plurality of the secondary batteries in series or in parallel is received or fixed in a box-shaped case or tray and is mounted on the electric vehicle, etc. Here, a lithium secondary battery is mainly used as the secondary battery.
The efficiency and performance of the battery module which is used in the electric vehicle, etc., depend greatly on a temperature. For example, when the battery is discharged at a high temperature, the lifespan of the battery is remarkably reduced. At a low temperature, the charging/discharging performance of the battery is degraded until the temperature reaches an appropriate temperature range required by the battery.
Accordingly, various tries are being made to appropriately maintain the current temperature of the battery module. One of the tries is a battery case (hereafter, referred to as a conventional battery case) disclosed in the Korean Patent number 10-1051446.
As shown in FIG. 1, the conventional battery case includes an inner case 10, an outer case 20, an elastic member 30 and a cooling fan 40. A battery module “P” obtained by combining a plurality of batteries in series or in parallel is received in the inner case 10.
The inner case 10 which has received the battery module “P” is received in the outer case 20. The outer case 20 is comprised of a control part installation portion 21 and a space for receiving the inner case 10. Control parts are installed in the control part installation portion 21. The cooling fan 40 for supplying cooling air to the space in which the inner case 10 has been received is installed on the front of the outer case 20, in which the control part installation portion 21 has been provided. Another cooling fan 40 for discharging the cooling air to the outside is installed on the rear of the outer case 20, on which the space for receiving the inner case 10 has been provided.
Meanwhile, in the conventional battery case, the elastic member 30 like a leaf spring is installed on the inner wall surface of the outer case 20, that is, the upper and lower surfaces and both inner sides respectively. When the inner case 10 which has received the battery module “P” is mounted, the outer surface of the inner case 10 comes in close contact with the middle portion of the elastic member 30 and is elastically supported.
Accordingly, the inner case 10 which has received the battery module “P” is elastically supported within the outer case 20 by the elastic member 30, so that vibration or impact which is applied to the outer case 20 can be prevented from being directly transmitted to the inner case 10. Simultaneously, the cooling air flows through a gap generated by the fact that the inner case 10 is spaced from the inner wall surface of the outer case 20 by the elastic member 30, so that the battery module “P” can be cooled.